1. Technical Field
The present invention relates generally to devices used to attach portable frames to hitches on vehicles used to transport such frames, and more specifically to a locking hitch pin including a threaded rod and a sleeve, connected to the threaded rod, to produce a one-piece, lockable bolt or pin used for essentially wobble-free connection of a receiving hitch to a portable frame. A protective housing is also provided that fits about the hitch pin and includes a locking device to prevent detachment of the housing and removal of the hitch pin.
2. Background Art
The attachment of load carrier frames at rearward portions of transport vehicles is well known, and especially for use as sports equipment carriers for bicycles and the like. Modern bicycles are expensive pieces of sports equipment and security becomes an issue when such equipment must be left unattended on a load carrier. A visible means of locking the equipment to the frame and the frame to the vehicle provides a deterrent to unauthorized removal.
Another problem associated with such load carrier frames when attached to vehicles occurs when rough terrain is encountered during travel. Since most carrier frames have multiple interconnected parts, including the connection to a vehicle hitch, the opportunity exists for the introduction of play or wobble between such parts. Depending on the extent of play or wobble, the load carrier frame may permit or generate movement that causes the equipment supported on the carrier to collide with the frame, its support structure, or the rear of the vehicle, ultimately resulting in damage to one or more of the colliding articles.
For at least those reasons mentioned above, it has become important to minimize the play and wobble associated with such load carrier frames and secure the carrier and sports equipment against theft.
U.S. Pat. No. 5,244,133 provides a description of a wobble-free trailer hitch mounting. The mounting fits inside the receiving opening of a receiver type hitch. At least a portion of the mounting responds to the rotation of a threaded rod to enlarge the effective width of the mounting. When positioned inside the receiving hitch, as its effective width increases, the mounting exerts pressure on the inner walls of the receiving hitch and this limits play between the mounting and the receiving hitch for reducing wobble in the connection.
The mounting of the ""133 patent comprises multiple parts and a relatively complex mechanism to increase the effective width of the mounting to exert wobble free gripping action against the receiving hitch. The disclosed structure also includes a padlock method to prevent unauthorized removal of the mounting from the hitch. This method is somewhat cumbersome and uses multiple separate pieces including a padlock and a hitch pin. Such a lockable hitch pin is well known and typically takes the form of a bolt that is passed through a receiving hitch and a mounting that is positioned inside the hitch. After passing through the hitch and emerging on the opposite side, a locking cap may be placed on the front end of the shaft and secured by a key. This lockable hitch pin, however, does not include an anti-wobble feature.
In view of the above described deficiencies associated with the designs and utilizations of known designs for supposed wobble-free, locking hitch mechanisms, the present invention has been developed to alleviate these drawbacks and provide further benefits to the user. These enhancements and benefits are described in greater detail hereinbelow with respect to several alternative embodiments of the present invention.
The present invention in its several disclosed embodiments alleviates the drawbacks described above with respect to conventionally designed anti-wobble mechanisms for hitch-mount load carriers that may be locked for security, and incorporates several additionally beneficial features. Features of particular interest include the provision of an anti-wobble device as part of the hitch pin itself and a lockable housing positioned over the hitch pin to provide environmental protection and prevent unauthorized entry.
The anti-wobble hitch pin has two primary parts, namely a threaded rod and a sleeve having a bore sized to matingly receive at least a portion of the threaded rod. A transverse pin lies across the bore with its ends held in contact with the wall of the sleeve. The transverse pin also passes through a longitudinal slot in the portion of the threaded rod received in the bore of the sleeve. In this position the transverse pin transmits any applied rotational force, from the sleeve to the rod causing these two parts to move together when rotated. At the same time, the longitudinal slot allows the rod to slide, to a limited extent, into and out of the bore of the sleeve. Such sliding motion is a controlled motion governed by a set screw engaging a threaded cup formed in the end of the rod lying inside the bore of the sleeve. A shoulder, protruding into the bore of the sleeve, separates this end of the rod from the head of the set screw. Application of turning motion to the set screw results in impingement of the screw head against one side of the shoulder and, with continued turning, the screw thread enters deeper into the threaded cup to draw the rod towards the other side of the shoulder and further into the bore of the sleeve.
A washer and a lock washer lie captive between the rod and the sleeve at the mouth of the sleeve. The secured combination of these several members provides a single unified article that replaces the multi-part units previously known and used for such securement purposes; that is, securement of a hitch-mount load carrier rack to a carrying vehicle.
The threaded end of the rod of this unified article passes through a hole in the side of the receiving hitch and a hole in a tubular mounting bar for the load carrier frame. After passing through a first side of the exterior tubular hitch portion and extending into the inserted tubular portion of the load carrier, the threaded end of the rod screwably engages a nut that is welded to the far inside surface of the inserted mounting bar of the carrier. Rotation of the sleeve and rod assembly draws the threaded rod into this nut until the washer impinges against the outer surface of the receiving hitch. Continued rotation of the rod then causes the outer surface of the inserted mounting bar to engage the opposed inner surface of the surrounding receiving hitch. Up to this point, the turning of the unified article has been preferably accomplished manually by an operator. As contact between the mounting bar surface and the inside of the receiving hitch increases, however, the unified article resists further hand tightening. At this stage, an allen wrench may be utilized to engage and further turn the set screw located in the sleeve thereby drawing the rod, over the transverse pin, further into the bore of the sleeve. This increases the gripping pressure exerted between the abutting portions of the mounting bar surface and the inside surface of the receiving hitch for the purpose of minimizing play between those components. A partial turn is generally sufficient to eliminate any remaining wobble associated with attachment of the carrier""s mounting bar to the receiving hitch of the transporting vehicle.
In at least one embodiment, the present invention takes the form of an anti-wobble hitch pin that includes a bolt having a head portion opposite a threaded section and a stem integrally formed between the head portion and the threaded section. The stem includes an elongate slot and the head portion has a threaded channel formed therein having a longitudinal axis in common with that of the bolt. A sleeve is provided that is sized to receive the head and the stem. The sleeve has a wall that includes an outer surface and an inner surface that defines an internal bore. The sleeve also has a groove formed in a wall opening to the inner surface and a ledge extending into the internal bore from the inner surface. The ledge has an inside face and an outside face and the head of the bolt is positioned adjacent to the inside face. A set screw is utilized that has a flat head and a threaded shaft. The threaded shaft is located inside the internal bore co-axial with the sleeve and is engaged in a threaded channel in the head of the threaded bolt. The flat head of the set screw is limited in movement by its abutment with the outer face of the ledge. A retaining ring is located in a groove of the sleeve and the flat head of the set screw is confined between the retaining ring and the outer face of the ledge. A transverse pin is held within the internal bore of the sleeve by attachment to the wall of the sleeve such that the transverse pin passes through the elongate slot of the stem to transmit rotational force from the sleeve to the bolt.
The beneficial effects described above apply generally to the exemplary devices and mechanisms disclosed herein of the anti-wobble hitch pin with its protective, lockable housing. The specific structures through which these benefits are delivered will be described in detail hereinbelow.